Howler-circuits for telephone-lines.



R. S. vWILBUR.

HOWLER cmcuns FOR TELEPHONE LINES.

APPLICATION FILED MAR. 18,1915.

Patented Sept. '24, 1918.

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scribed as follows: Assume that the re ceiver at the substation A hasbeen inadvertently left off the switchhook. Through the energizationofthe line relay- 4, the line lamp 5 would be permanent at some point onthe switchboard. The operator upon failure to receive any response whenchallenging the subscribers attention, would then insert the plug 7(assuming that each operators position is provided with one of theseplugs) into the line jack 3. This act on the part of the operator wouldcomplete the following circuit: battery 39, coil of relay 38, conductor37, contact 36, conductor 35, winding of the relay 34, conductors 33,32, sleeve side of the plug 7 and jack 3 respec tively, conductor 31,coil of relay 6, to ground. Upon the closure of this circuit the relays34 and 38 are actuated, the latter of which, in pulling up itsarmatures, closes a contact which establishes the following circuit forthe interrupter 8: battery9, primary winding 15 of the trans-former 10,conductor 59, contact 60, conductor 61, interrupter 8, to ground. If atthis time the cam 13 of the contact member 12 happened to be engagingthe resilient member 41, the contact 14 will thereby be closed, whichcompletes the following circuit: battery 40, member 41, contact 14,conductor 42, contact'43, conductor 44, winding 21 of relay 23, toground, thus causing the relay 23 to be actuated. The energization ofthe relay 23' closes contacts. 24, 25 and 26, and opens the contact 36,thereby altering previous circuit conditions in the following manner:The opening of the contact 36 and closing of, the contact 24 causes thedeenergization of the relay 34, and the establishment of a circuit forthe relay 28, which circuit may be traced as follows: battery 39,'coilof relay 38, conductor 37, contact 24, conductor 27 the winding ofrelay28, conductors 29, 32, sleeve side of the plug 7 and jack 3respectively, conductor 31, coil of relay 6, to ground. The actuation ofrelay 28 closes contacts 30 and 55, thereby connecting relay 23 in thesubscribers line circuit which may be traced as follows: battery 45,winding 22 of relay 23, conductor 47 contact 30, conductor 49, secondarywinding 19 of the repeating coil 17 conductor 50,- contact 25,conductor51, line wire 2, through the substation A and back over linewire 1, conductor 52, contact 26, .conductor 53, secondarywinding 19,con- 'ductor 54, contact 55, conductor 56, winding 21 of relay 23,.toground. It will be noted that the energization of the relay 23 is nowdependent upon the receiver at the substation A being removed from theswitchhook. The qualityof the howler tone which is sent out to thesubscribers station asthe contact member 12 engages the contacts 11, 11,will depend upon which one of the arrangements hereinbefore described isemployed.

It will be noted that the contact 14 is opened upon the disengagement ofthe cam "13 with the resilient member 41, and that before the relay 23-can be originally ener gized, the contact 14 must be closed. Thisfeature prevents the application of the howler tone to a subscribersline when said tone 1s at-its maximum volume it being" in.

operable unless the howler tone is faint or has temporarily beencompletely removed. It will also be noted that upon the energization ofthe relay 23, through the openingof the contact 36, the relay 34 isdeenergized', thereby extinguishing the lamp '58 whose circuit iscontrolled by the relay 34.

.When the receiverv at the substation A is replaced upon the switchhookthe energizing circuit for the relay 23 isinterrupted and thede'energization of this relay is insured by the contact member 12engaging some of the contacts 11, 11 left vacant. These vacantcontacts-preclude any possibility of. the current.

induced through the secondary winding 19 of the repeating coil17 frommaintaining thereby 'reestablishing the circuit for the relay 34described above. The actuation of the relay 34 closes the contact 57,thereby completing a circuit through the lamp "58 from the battery 56.The re-. lay 34 is preferably of the type slow in re,- leasing, so thatin event the subscriber at substation A worked his receiver hook up anddown to attract the attention of the operator, the lamp 58 would not beflashed by the interruption of its circuit upon the energization anddeenergization of the relay 34 causedby the subscribers action From theabove it will be apparent that by the means provided in this invention ahowler tone may be applied to a subscribers line on which the receiverhas been inadvertently removed, without incurring the danger of applyinga howler tone of considerable volume to the subscribers line at a timewhen the subscriber may happen to have the receiver to his ear. I What.is claimed is: a

1. In a telephone exchange system, a telephone line, a tone producingmeans including an inducto'riumehaving its secondary divided intosections, and means for automatically-and variably associating saidsecondary sections with said line.

2. In a telephone exchange system, a tele- 3. In a telephone exchangesystem, a telephone line, an auxiliary circuit, switching means forconnecting said auxiliary circuit with said telephone line, a toneproducing circuit including an inductorium primary controlled byconnection of said auxiliary circuit with said telephone line, aninductorium secondary divided into sections, means for associating saidsecondary with said line, and means for increasing the number ofeflective sections of said secondary after said secondary has beenconnected to said line.

I. In a telephone exchange system, a telephone line, an auxiliarycircuit, switching means for connecting said auxiliary circuit with saidtelephone line, a tone producing circuit including an inductoriumprimary controlled by connection of said auxiliary circuit with saidtelephone line, an inductorium secondary divided into sections, acircuit and connections for associating said secondary with saidtelephone line, and means for increasing the number of effectivesections of said secondary after said secondary has been connected tosaid line.

5. In a telephone exchange system, a telephone line, an auxiliarycircuit, switching means for connecting said auxiliary circuit with saidtelephone line, a tone producing circuit including an inductoriumprimary controlled by connection of said auxiliary circuit with saidtelephone line, an inductorium secondary divided into sections, contactmembers to which the separate sections of said secondary are connected,a rotatable arm adapted to wipe over said contacts to gradually increasethe number of effective to which the secondary sections are joined,

a source of intermittent current in circuitwith the primary of theinductorium, means for connecting the secondary with the telephone line,and a brush traveling over the fixed contacts to vary the number ofsecondary sections in circuit thereby to vary the strength of currenttraversing the telephone line.

7. In a telephone excht nge system, a telephone line, a source ofintermittent current, sectional controlling means traversed by suchcurrent, means for inductively associating the sectional controllingmeans with the telephone line, and a traveling member for varying thenumber of controlling sections in circuit with the source of current andfor rendering successive controlling sections active, thereby to varythe strength of cur rent traversing the line.

In witness whereof, I hereunto subscribe my name this 16th day of MarchA. D., 1915.

RAY SETH WILBUR. Witnesses:

E. EDLER, K. L. STAHL.

Copies 0! this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

, Washington, D. G.

